9.　as it were 常插在句子中，表示‘姑且这样说，可说是’这类的意思

He is a grown-up baby, as it were . 他可说是一个大孩子了

He became, as it were a kind of hero from a strange land. 他仿佛成了一个来自异乡的英雄

he was, as it were , intoxicated by the soft air and sunshine of spring. 他可说是被春天的和风和阳光陶醉了

8.　 need / needn’t + have done 结构也可以表示虚拟语气，作‘本来有/没有必要做某事’

7.　不定式的完成时用在 intend , mean , plan , suppose 等动词后，表示原打算做而实际未能做而实际未能做成的事，因而含有虚拟的意思

6.　 need “不必做”和“本不必做”

didn't need to do表示过去不必做某事, 事实上也没做；needn't have done表示过去不必做某事, 但事实上做了

John went to the station with the car to meet Mary, so she didn't need to walk back home.

约翰开车去车站接玛丽，所以她不必步行回家了

John went to the station with the car to meet Mary, so she needn't have walked back home.

约翰开车去车站接玛丽，所以她本不必步行回家了。 (Mary步行回家了，没有遇上John的车)

[典型例题]

There was plenty of time. She ___.

A. mustn't have hurried　 　　　　　B. couldn't have hurried

C. must not hurry　　　　　　　　　 D. needn't have hurried

[解析] D needn't have done. 意为"本不必"，即已经做了某事，而时实际上不必要。Mustn't have done 用法不正确，对过去发生的事情进行否定性推断应为couldn't have done, "不可能已经"。must not do 不可以(用于一般现在时)

5.　but 或 but that 表达的含蓄条件的特殊含义

but 或 but that 做“如果不……”解，意思相当与“if not”，其后面不可接虚拟模式，应接陈述式的现在时动词或过去时动词，即‘but that + 主语 + 现在时动词 / 过去式动词’，而主句要用虚拟式。

But that you help him , he would fail . 如果没有你的帮助，他会失败的

But that you helped him , he would have failed . 如果没有你的帮助，他早就失败了

4.　比较if only与only if

only if表示"只有"；if only则表示"如果……就好了"。If only引起的句子，一般过去时或would+动词原形表示现在或未来事实相反，过去完成时表示与过去事实相反，也可用于陈述语气

I wake up only if the alarm clock rings. 只有闹钟响了，我才会醒。

If only the alarm clock had rung.　　 当时闹钟响就好了。

If only he comes early.　　　　　 但愿他早点回来

If only we knew where to look for him.　 我们要是知道到哪里去找他就好了

If only I had listened to my parents.　 要是我听取了父母的话该多好啊

3.　虚拟语气用在It is(about ／high)time +that定语从句中

在It is(about／high)time +that定语从句中需用虚拟语气，表示“该做……的时候了”，其动词形式用一般过去时或should +动词原形

It's already 5 o'clock now,Don't you think it's about time we went home？已经5点钟了，你不认为我们应该回家了吗？

[点拨]①在this is the first time ／second time that．．．句型中，从句中谓语动词用陈述语气完成时态

Is this the first time that you have visited Hongkong？这是你第一次参观香港吗？

②It's time to do something有别于It's time that．．．

2.　虚拟语气用在It is +过去分词+that的主语从句中

在It is +过去分词+that的主语从句中，常用虚拟语气，表示愿望、建议、请求等主观意向，谓语用 should +动词原形或省略should只用动词原形。这类过去分词有：decided，demanded，desired，insisted，ordered，proposed，suggested，recommended，requested， required等。

It is desired that we(should)get everything ready this evening．希望我们今晚一切都准备就绪。

1.　虚拟语气用在It is +形容词+that的主语从句中

在某些表示愿望、建议、请求、命令等形容词后的主语从句中，需用虚拟语气。其表达形式为should +动词原形或省略should直接用动词原形。这类形容词有 advisable(合理的)，appropriate(适当的)，compulsory(必须的)，crucial(紧急的)，desirable(理想的)，essential(必要的)，imperative(迫切的)，important(重要的)，incredible(惊人的)，natural(自然的)，necessary(必要的)，possible(可能的)，preferable(更好的)， probable(可能的)，strange(奇怪的)，urgent(紧迫的)， vital(极为重要的)。

It is essential that these application forms be sent back as early as possible．这些申请表应尽早地寄回，这是很重要的。

It is vital that enough money be collected to fund the project．重要的是募集足够的钱，为这个项目提供资金。

在书面语中，如果条件从句含有 were, had, should，可将连词 if 省略，再将 were, had 或 should 移至句首，构成非真实条件句的倒装语序

Were they here now, they could help us. =If they were here now, they could help us.他们现在在的话，就会帮助我们了。

Had you come earlier, you would have met him. =If you had come earlier, you would have met him.

你来得早一点，就碰到他了。

Should it rain, the crops would be saved. =Were it to rain, the crops would be saved.假如下雨，庄稼就有救了。

[典型例题]

_____ to do the work, I should do it some other day.　　

A. If were I　　　 B. I were　　　 C. Were I　 D. Was I

答案C. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成 were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说Were I not to do, 而不能说 Weren't I to do.

e.g.　 Had you been here just now, you would have met her. 你要是刚才在这儿，就见到她了。

Were I not busy, I would have come. 假如我不忙，我就会来了。